Traditionally, there has been known a work vehicle such as a tractor having a structure including a hydraulic continuously variable transmission for smooth traveling in a field. Patent Literatures 1 and 2 (hereinafter referred to as PTL 1 and PTL 2, respectively) each discloses a work vehicle (tractor) having such a hydraulic continuously variable transmission.
The tractor disclosed in PTL 1 includes a hydraulic continuously variable transmission having a hydraulic pump and a hydraulic motor. The hydraulic pump is driven by a power of the engine to generate hydraulic pressure. The hydraulic motor converts the hydraulic pressure generated by the hydraulic pump into rotational force. Further, the hydraulic pump has a movable swash plate, and by changing a working fluid delivery rate according to the inclination angle of the movable swash plate, speed can be changed.
Further, the tractor of the PTL 1 has a gear shift lever for instructing a target speed. When the gear shift lever is operated by an operator, the expansion/contraction amount of a hydraulic cylinder changes according to the lever position. This way, the inclination angle of the movable swash plate can be changed according to the speed instructed by the operator.
The tractor of PTL 2 includes a reverser lever. By operating the reverser lever, the operator can instruct advance, reverse, and neutral. When the reverser lever is operated by the operator, a gear shift actuator is driven according to the lever position, thereby changing the inclination angle of the movable swash plate. For example, when the operator instructs neutral by operating the reverser lever, the inclination angle of the movable swash plate (delivery rate of the hydraulic pump) is changed so that the power of the engine is not transmitted to the output shaft of the hydraulic continuously variable transmission. It should be noted that PTL 2 does not disclose a specific structure of the gear shift actuator.